The record storage film having triacetyl cellulose (TAC) as the base film (hereinafter, referred to as the “TAC film”) thereof is used for the purpose of recording and preserving various historical data, documents or the like, in a form of, for example, “cinematographic films”, “microfilms”, or “photographic films”. As compared with the nitrocellulose film used in the past, the TAC film is higher in flame resistance and referred to as a safety film, and has also been considered to be preserved for 100 years or more.
However, it has recently been revealed that a phenomenon referred to as vinegar syndrome occurs in common preservation environments, and the deterioration of the TAC film starts within approximately 30 years. When a TAC film is preserved in high-temperature and high-humidity environments, the hydrolysis of TAC occurs due to the factors such as temperature and humidity, and consequently acetic acid gas is generated. The acetic acid gas acts as a catalyst and promote the hydrolysis reaction of TAC. The vinegar syndrome indicates a rapid deterioration phenomenon of the film caused by such a hydrolysis of TAC.
With respect to such a vinegar syndrome, in order to prevent the deterioration of the TAC film, it has hitherto been performed to preserve a TAC film together with a humidity-controlling/gas-absorbing molded article including a gas-absorbing composition containing MgO and Al2O3 (see, for example, Patent Literature 1 (Japanese Patent Laid-Open No, H08-217913)). The present applicant has also proposed a film deterioration preventing material containing a carboxylate salt as an acetic acid gas removing agent (for example, see Patent Literature 2 (Japanese Patent Laid-Open No. 2013-104030)). The film deterioration preventing material absorbs a larger amount of acetic acid gas and removes the acetic acid gas more rapidly, as compared with the humidity-controlling/gas-absorbing molded article described in Patent Literature 1. Accordingly, by placing and preserving a TAC film together with the film deterioration preventing material in a preservation container, the deterioration of the TAC film can be effectively suppressed.